A pinch valve is a valve operable with a flexible tubing or hose, which is capable of pinching the tube or hose using a tube-pinching mechanism. Pinch valves are typically full bore, linear action valves that can be used in an off/on manner. However, some pinch valves can be used in a variable position or throttling service.
Pinch valves are used in many medical and pharmaceutical applications. They are also used in food dispensing applications because a main advantage of pinch valves is that they facilitate cleanliness, excellent drainage, and ease of cleaning. In addition to cleanliness, another advantage of pinch valves is their operation speed. Most pinch valves are simply on-off valves; they open and close a flexible tube using a pinch bar that moves between two positions. Moving a pinch bar through two, fixed locations can be done quickly, especially if the pinch bar is moved by an electrically-actuated solenoid.
Electromechanical closure of a pinch valve is typically accomplished by activating a solenoid to draw a spring-biased bar or gate against an elastomeric sleeve or tube, thereby cutting off fluid flow through the tube or sleeve. Some prior art pinch valves are fluid actuated wherein the pinching action is accomplished by air or hydraulic pressure placed on the elastomeric sleeve or tube.
A problem with prior art pinch valves, especially those used with food and liquid dispensers, is that they do not facilitate the installation and removal of a bulk container. Stated another way, prior art pinch valves typically require disassembly to install and/or remove a tube passing through them and also for cleaning.